FMULX

Floating-point multiply extended

This instruction multiplies corresponding floating-point values in the vectors of the two source SIMD&FP registers, places the resulting floating-point values in a vector, and writes the vector to the destination SIMD&FP register.

If one value is zero and the other value is infinite, the result is 2.0. In this case, the result is negative if only one of the values is negative, otherwise the result is positive.

This instruction can generate a floating-point exception. Depending on the settings in FPCR, the exception results in either a flag being set in FPSR or a synchronous exception being generated. For more information, see Floating-point exceptions and exception traps.

Depending on the settings in the CPACR_EL1, CPTR_EL2, and CPTR_EL3 registers, and the current Security state and Exception level, an attempt to execute the instruction might be trapped.

It has encodings from 4 classes: Scalar half-precision , Scalar single-precision and double-precision , Vector half-precision and Vector single-precision and double-precision

Scalar half-precision
(FEAT_AdvSIMD && FEAT_FP16)

Decode for this encoding

if !IsFeatureImplemented(FEAT_AdvSIMD) || !IsFeatureImplemented(FEAT_FP16) then EndOfDecode(Decode_UNDEF); constant integer d = UInt(Rd); constant integer n = UInt(Rn); constant integer m = UInt(Rm); constant integer esize = 16; constant integer datasize = esize; constant integer elements = 1;

Scalar single-precision and double-precision
(FEAT_AdvSIMD)

Decode for this encoding

if !IsFeatureImplemented(FEAT_AdvSIMD) then EndOfDecode(Decode_UNDEF); constant integer d = UInt(Rd); constant integer n = UInt(Rn); constant integer m = UInt(Rm); constant integer esize = 32 << UInt(sz); constant integer datasize = esize; constant integer elements = 1;

Vector half-precision
(FEAT_AdvSIMD && FEAT_FP16)

Decode for this encoding

if !IsFeatureImplemented(FEAT_AdvSIMD) || !IsFeatureImplemented(FEAT_FP16) then EndOfDecode(Decode_UNDEF); constant integer d = UInt(Rd); constant integer n = UInt(Rn); constant integer m = UInt(Rm); constant integer esize = 16; constant integer datasize = 64 << UInt(Q); constant integer elements = datasize DIV esize;

Vector single-precision and double-precision
(FEAT_AdvSIMD)

Decode for this encoding

if !IsFeatureImplemented(FEAT_AdvSIMD) then EndOfDecode(Decode_UNDEF); if sz:Q == '10' then EndOfDecode(Decode_UNDEF); constant integer d = UInt(Rd); constant integer n = UInt(Rn); constant integer m = UInt(Rm); constant integer esize = 32 << UInt(sz); constant integer datasize = 64 << UInt(Q); constant integer elements = datasize DIV esize;